Gold- and Platinum-Bearing Minerals of the Late Mesozoic Ariadne Ultramafic Massif (Sikhote-Alin Orogenic Belt)

Gold-platinum mineralization was discovered in ultramafic–mafic rocks of the Ariadne massif of the Sikhote-Alin orogenic belt. In this article, we show that ultramafic (peridotite and pyroxenite) and mafic (ilmenite and hornblende gabbro) rocks form a single series with gradual accumulation of rare and rare earth elements of more differentiated varieties. New age determinations for zircon from ilmenite gabbro are given (164 ± 0.48 Ma). We distinguished four varieties of gold differing in the Au, Ag, Cu, and Hg contents. Platinum-bearing minerals are isoferroplatinum and cuprite. The isotopic composition of sulfides from ultramafic rocks suggests a mantle source, while sulfides from ilmenite gabbros are characterized by isotopically light sulfur, indicating the possible involvement of crustal rocks in ore genesis. Carbon isotope analysis of the carbon-bearing matter of mafic–ultramafic rocks showed the presence of mantle fluids and isotopically light biogenic matter from sedimentary rocks. The data indicate the influence of mantle and crustal processes on the formation of ore-bearing mafic and ultramafic intrusions.